Optical Coherence Tomography News

Feature Of The Week

Three-dimensional (3D) tumor spheroid models have gained increased recognition as important tools in cancer research and anti-cancer drug development. However, currently available imaging approaches employed in high-throughput screening drug discovery platforms e.g. bright field, phase contrast, and fluorescence microscopies, are unable to resolve 3D structures deep inside (>50 μm) tumor spheroids. In this study, we established a label-free, non-invasive optical coherence tomography (OCT) imaging platform to characterize 3D morphological and physiological information of multicellular tumor spheroids (MCTS) growing from ~250 μm up to ~600 μm in height over 21 days. In particular, tumor spheroids of two cell lines glioblastoma (U-87 MG) and colorectal carcinoma (HCT 116) exhibited distinctive evolutions in their geometric shapes at late growth stages. Volumes of MCTS were accurately quantified using a voxel-based approach without presumptions of their geometries. In contrast, conventional diameter-based volume calculations assuming perfect spherical shape resulted in large quantification errors. Furthermore, we successfully detected necrotic regions within these tumor spheroids based on increased intrinsic optical attenuation, suggesting a promising alternative of label-free viability tests in tumor spheroids. Therefore, OCT can serve as a promising imaging modality to characterize morphological and physiological features of MCTS, showing great potential for high-throughput drug screening.

For more information see recent Article. Courtesy Chao Zhou from Lehigh University. To share this article click Here.
Featured Articles
1. Advances in intraoperative optical coherence tomography for surgical guidance
  
  Explore ScienceDirect Oct 14 2017
  
  Translation of optical coherence tomography (OCT) technologies for intraoperative visualization enables in vivo micron-resolution imaging of subsurface tissue structures and image-guided clinical decision-making. Over the last decade, intraoperative OCT has evolved from two-dimensional imaging using handheld probes to include biopsy-needles for minimally invasive deep-tissue imaging, surgical instrumentation using optical feedback for tremor dampening and stabilization, and stereomicroscope integrated systems that provide real-time three- and four-dimensional visualization of surgical maneuvers. In addition, several preliminary studies have demonstrated the feasibility and utility of combining intraoperative OCT imaging with novel image-processing and display methods to implement augmented/virtual reality and robotic surgical guidance ...
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  Mentions: Vanderbilt University Yuankai K. Tao
2. Postdoctoral Fellow Positions at Case Western Reserve University
  
  Explore Optical Coherence Tomography News Oct 13 2017 Jobs & Studentships
  
  Location: Case Western Reserve University, Cleveland, OH, 44106-7080 Application Deadline: Open until filled, available immediately Job description: Post-doctoral research training positions available immediately to join a team of biomedical engineers, neurobiologists, and electrophysiologists to assess the mechanisms by which infrared light (infrared neuromodulation - IRN) can modulate axons and neurons in ganglia as a therapeutic alternative to systemic drug delivery, as well as creating novel tools for visualizing and manipulating neurons and axons using infrared light. Successful applicants will be expected to work in an interdisciplinary team, including coordination with research and clinical collaborators and providing leadership to junior researchers. Outstanding ...
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  Mentions: Case Western Reserve University Michael W. Jenkins
3. Postdoctoral Research Fellowship in Biomedical Optics at CNRS/Strasbourg University
  
  Explore Optical Coherence Tomography News Oct 12 2017 Jobs & Studentships
  
  Applicants are invited to apply for a postdoctoral researcher position in optical imaging systems for biomedical applications. The project involves the development of the novel catheter-based OCT imaging system to enhance the robotized interventional endoscope for diagnosing and treatment of diseases in the digestive system. The successful candidate will work with the research group supported by the ATIP-Avenir grant awarded by the French National Center for Scientific Research (CNRS) and the French National Institute of Health and Medical Research (INSERM). The group is focused on highly interdisciplinary projects that bridge photonics and robotics to improve performance of microscopic imaging modalities ...
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  Mentions: Michalina J. Góra
4. Investigating the healing mechanisms of an angiogenesis-promoting topical treatment for diabetic wounds using multimodal microscopy
  
  Explore Wiley Online Library Oct 5 2017 Dermatology
  
  Impaired skin wound healing is a significant co-morbid condition of diabetes that is caused by poor microcirculation, among other factors. Studies have shown that angiogenesis, a critical step in the wound healing process in diabetic wounds, can be promoted under hypoxia. In this study, an angiogenesis-promoting topical treatment for diabetic wounds, which promotes angiogenesis by mimicking a hypoxic environment via inhibition of prolyl hydroxylase resulting in elevation or maintenance of hypoxia inducible factor (HIF), was investigated utilizing a custom-built multimodal microscopy system equipped with phase-variance optical coherence tomography (PV-OCT) and fluorescence lifetime imaging microscopy (FLIM). PV-OCT was used to track ...
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  Mentions: Stephen A. Boppart University of Illinois at Urbana-Champaign Eric J. Chaney
5. Computer-aided detection of early Barrett’s neoplasia using volumetric laser endomicroscopy
  
  Explore Gastrointestinal Endoscopy Oct 4 2017 Gastroenterology
  
  Background and Aims Volumetric laser endomicroscopy (VLE) is an advanced imaging system that provides a near-microscopic resolution scan of the esophageal wall layers up to 3-mm deep. VLE has the potential to improve detection of early neoplasia in Barrett’s esophagus (BE). However, interpretation of VLE images is complex because of the large amount of data that need to be interpreted in real time. The aim of this study was to investigate the feasibility of a computer algorithm to identify early BE neoplasia on ex vivo VLE images. Methods We used 60 VLE images from a database of high-quality ex ...
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6. Feature Of The Week 10/1/2017: Optical Coherence Tomography: from Healthcare Idea to Healthcare Impact.
  
  Explore Optical Coherence Tomography News Oct 1 2017
  
  The commercialization and growth of OCT which has occurred over the past 25 years has been highly impactful scientifically, clinically, and economically. Many factors have helped drive this success starting with the clinical need for new cost-effective high-resolution minimally-invasive imaging solutions for various diagnostic and therapeutic applications. But equally important to this success was the intertwined role of researchers, engineers, clinicians, professional societies, government agencies, government funding, regulatory bodies, entrepreneurs, venture capitalists, and small and large corporate entities within the biomedical optics industry and other industries. This talk will review some of the history of the commercialization of OCT and ...
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  Mentions: Massachusetts Institute of Technology James G. Fujimoto Eric A. Swanson
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Recent Articles From Around The Web
1. OCT Made Easy (Textbook)
  
  Explore CRC Press Online 16 hours, 15 min ago Cardiology , Textbooks
  
  This book, written by premier authors in the field of OCT intravascular imaging, covers the best practices for using OCT to provide high resolution cross-sectional viewing for atherosclerotic plaque assessment, stent strut coverage and apposition, assessment in stent restenosis evaluation, and PCI guide and optimization. Fully illustrated thorughout in a handy, cath-lab side handbook supplemented by online movie clips, OCT Made Easy includes case studies, angiography, CT correlations, and simple techniques for getting the best image.
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  Mentions: Case Western Reserve University Marco A. Costa Hiram G. Bezerra
2. 3D Mapping of Choroidal Thickness from OCT B-Scans
  
  Explore Home - Springer 16 hours, 16 min ago Ophthalmology
  
  The choroid is the middle layer of the eye globe located between the retina and the sclera. It is proven that choroidal thickness is a sign of multiple eye diseases. Optical Coherence Tomography (OCT) is an imaging technique that allows the visualization of tomographic images of near surface tissues like those in the eye globe. The automatic calculation of the choroidal thickness reduces the subjectivity of manual image analysis as well as the time of large scale measurements. In this paper, a method for the automatic estimation of the choroidal thickness from OCT images is presented. The pre-processing of the ...
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3. Multi-layer 3D Simultaneous Retinal OCT Layer Segmentation: Just-Enough Interaction for Routine Clinical Use
  
  Explore Home - Springer 16 hours, 18 min ago Ophthalmology
  
  All current fully automated retinal layer segmentation methods fail in some subset of clinical 3D Optical Coherence Tomography (OCT) datasets, especially in the presence of appearance-modifying retinal diseases like Age-related Macular Degeneration (AMD), Diabetic Macular Edema (DME), and others. In the presence of local or regional failures, the only current remedy is to edit the obtained segmentation in a slice-by-slice manner. This is a very tedious and time-demanding process, which prevents the use of quantitative retinal image analysis in clinical setting. In turn, the non-existence of reliable retinal layer segmentation methods substantially limits the use of precision medicine concepts in ...
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  Mentions: Michael D. Abràmoff University of Iowa Milan Sonka
4. Optical Coherence Tomography Denoising by Means of a Fourier Butterworth Filter-Based Approach
  
  Explore Home - Springer 16 hours, 19 min ago
  
  Optical Coherence Tomography (OCT) is affected by ubiquitous speckle noise that difficult the visualization and analysis of the retinal structures. Any denoising strategy should be able to remove efficiently the noise as well as preserves clinical information contained in the images. This information is crucial to analyses the retinal layer tissue that allows the posterior analysis and recognition of relevant diseases as macular edema or diabetic retinopathy. To address this issue, a method based on the Fourier Butterworth filter combined with a contrast enhancement and a histogram regularization was developed in order to reduce the speckle noise in OCT retinal ...
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5. Feature Definition and Selection for Epiretinal Membrane Characterization in Optical Coherence Tomography Images
  
  Explore Home - Springer 16 hours, 20 min ago
  
  Optical Coherence Tomography (OCT) is a common imaging technique for the detection and analysis of optical diseases, since it is a non invasive method that generates in vivo a cross-sectional visualization of the retinal tissues. These characteristics contributed to the use of OCT imaging in the analysis of pathologies as, for instance, vitreomacular traction, age-related macular degeneration or hypertension. Among its applications, OCT imaging can be used in the detection of any present epiretinal membrane section in the retina, a critical issue to prevent further complications caused by this pathology. This work analyzed the main characteristics of the epiretinal membrane ...
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6. Resin infiltration analysis into carious lesions by optical coherence tomography
  
  Explore Dental Materials 16 hours, 24 min ago Dentistry
  
  Purpose/aim: The minimally invasive approach claims for the detection and treatment of early caries lesions. Resin infiltrant materials can penetrate into porosities of the lesion body by capillary forces, preventing the progression of white spot lesions, improving esthetic and providing support to enamel. It is suggested that optical coherence tomography (OCT) could assess penetration depth of the resin infiltrant into white spots lesions, which may provide information about the lesion's progression.
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  Mentions: Anderson Z. Freitas
7. OCT Angiography (Textbook)
  
  Explore thieme-connect.de 18 hours, 29 min ago Ophthalmology , Textbooks
  
  Textbook on OCT Angiography.
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8. Hybrid Deep Learning on Single Wide-field Optical Coherence Tomography Scans Accurately Classifies Glaucoma Suspects
  
  Explore LWW Online Oct 19 2017 Ophthalmology
  
  Purpose: Existing summary statistics based upon optical coherence tomographic (OCT) scans and/or visual fields (VFs) are suboptimal for distinguishing between healthy and glaucomatous eyes in the clinic. This study evaluates the extent to which a hybrid deep learning method (HDLM), combined with a single wide-field OCT protocol, can distinguish eyes previously classified as either healthy suspects or mild glaucoma. Methods: In total, 102 eyes from 102 patients, with or suspected open-angle glaucoma, had previously been classified by 2 glaucoma experts as either glaucomatous (57 eyes) or healthy/suspects (45 eyes). The HDLM had access only to information from a ...
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  Mentions: Cornell University Columbia University Robert Ritch
9. Avinger Announces First Patient Enrolled in its IDE Study of the Pantheris Image-Guided Atherectomy System for Treatment of In-Stent Restenosis
  
  Explore Optical Coherence Tomography News Oct 19 2017 Cardiology , Other Business News
  
  Avinger, Inc. (NASDAQ:AVGR), a leading developer of innovative treatments for Peripheral Artery Disease (PAD), today announced initiation of INSIGHT, a prospective, global, single arm, multi-center study to evaluate the safety and effectiveness of the Pantheris® Lumivascular Atherectomy System for treating in-stent restenosis (ISR) in lower extremity arteries. Up to 140 patients will be enrolled in the INSIGHT trial at up to 20 U.S. and international centers. Sean Janzer, M.D. of Einstein Medical Center and Glen Schwartzberg, M.D. of Baton Rouge General Medical Center serve as co-principal investigators of the study. In-stent restenosis occurs when a blocked ...
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  Mentions: John B. Simpson Avinger
10. The Role of Optical Coherence Tomography Angiography in Polypoidal Choroidal Vasculopathy
  
  Explore The JAMA Network Oct 19 2017 Ophthalmology
  
  Retinal imaging technology has progressed rapidly in recent years and plays increasingly vital roles in guiding the clinical management of retinal diseases, as well as facilitating greater understanding of the disease process. Polypoidal choroidal vasculopathy (PCV) is an important variant of neovascular age-related macular degeneration with distinct phenotypic features that can be seen both on clinical examination and using indocyanine green angiography (ICGA). In this issue of JAMA Ophthalmology, the optical coherence tomography angiography (OCTA) features of PCV are described and evaluated by Chi et al.¹
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11. Development of a Free Space, LED Illuminated Spectral-domain Optical Coherence Tomography Setup
  
  Explore hrpub.org Oct 18 2017
  
  Free-space spectral domain optical coherence tomography has been demonstrated using an 8 mW ultra-bright 850 nm light-emitting diode with a 40 nm spectral width. The system detects longitudinal reflectivity of surface and sub-surface layers of optical elements to depths of a millimetre with high fidelity. Development stages included mathematical analysis of light interference by superposition of electric field phasors of reference and sample arms of a Michelson interferometer. A method by which depth-resolved reflectivity is acquired is described. A locally assembled Czerny Turner monochromator was aligned such that the interferometer output beam is dispersed into its spectral components before image ...
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12. Design and Implementation of Full Field-Optical Coherence Tomography on an Olympus IX73 Microscope (Thesis)
  
  Explore MSpace Home Oct 18 2017 Student Theses
  
  Optical Coherence Tomography (OCT) has established itself as an important imaging technology for biomedical and industrial applications. In this thesis, we describe the design and implementation of a novel Full-Field OCT optical module that is specifically designed to fit inside an Olympus IX73 inverted microscope. We describe the design, components, and implementation of this novel optical module in detail. The resulting FF-OCT setup (microscope and OCT optical module) can be used as either a Time-Domain system or a Fourier-Domain (swept-source) system, without the need for considerable changes to the OCT optical module. However, we used our FF-OCT setup to implement ...
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  Mentions: University of Manitoba Olympus
13. Retinal Changes in Different Grades of Retinal Artery Occlusion: An Optical Coherence Tomography Study
  
  Explore IOVS Journal Oct 18 2017 Ophthalmology
  
  Purpose : To investigate layer-by-layer changes in retinal thickness and reflectivity regarding the severity grade of acute retinal artery occlusion (RAO) using spectral-domain optical coherence tomography (SD-OCT). Methods : This study is a retrospective, observational case-control series that took place in an institutional setting and included 148 eyes from 74 patients diagnosed with acute RAO (central or branch). SD-OCT examinations were taken at baseline. Based on OCT findings, RAO was categorized into three grades (incomplete, subtotal, total). The thickness and reflectivity of selected retinal layers were measured from SD-OCT images. The data were compared across the three grades and against the contralateral ...
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14. Optical Coherence Tomography Angiography in the Evaluation of Geographic Atrophy Area Extension
  
  Explore IOVS Journal Oct 18 2017 Ophthalmology
  
  Purpose : To investigate the application of optical coherence tomography angiography (OCT-A) in evaluation of geographic atrophy (GA) secondary to age-related macular degeneration (AMD). Methods : Patients with GA were prospectively enrolled and studied with blue fundus autofluorescence (FAF), en face structural OCT, and OCT-A. OCT-A images were acquired using a slab of whole choroid, whereas en face structural OCT images were obtained at the ellipsoid zone (EZ), at the choroidal (CH) level, and at the scleral (SC) level. Three readers independently measured the GA extension areas and evaluated the foveal sparing in each examination. Intraobserver/interobserver agreements and agreement between each ...
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  Mentions: Centre Hospitalier Intercommunal de Créteil Giuseppe Querques Francesco Bandello
15. Noninvasive structural and microvascular anatomy of oral mucosae using handheld optical coherence tomography
  
  Explore OSA | OSA Publishing Oct 18 2017
  
  In this study, we demonstrated the feasibility of using a handheld optical coherence tomography (OCT) for in vivo visualizations of the microstructural and microvascular features of various oral mucosal types. To scan arbitrary locations of the oral mucosa, a scanning probe was developed, composed of a probe body fabricated by a 3D printer, miniaturized two-axis galvanometer, relay lenses, and reflective prism. With a 3D printing technique, the probe weight and the system volume were greatly reduced, enabling the effective improvement of imaging artifacts from unconscious motion and system complexity. Additionally, in our design, the distal end of the probe can ...
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  Mentions: National Taiwan University Meng-Tsan Tsai Chang Gung University